Distortion algorithm “feedback” with guitar

[amop]

Hello –

I’ve been starting to use my guitar with the H9000 (guitar to audio interface with instrument setting, adat send/return to H9000) and with every distortion algorithm by default I get incredible screeching “feedback” (even though listening with headphones).  I can make adjustments to mitigate this but then usually it reduces the effect to an unwanted weakness.  I can’t figure out what would cause this.

Any possible cause of this?  I wasn’t expecting this in an effects unit using headphones where actual feedback couldn’t be the culprit.

thanks!

[tbskoglund]

Hello,

Can you be more specific with how your routing is setup? It may be that you have created a routing feedback loop, and when you load a distortion algorithm this becomes more apparent because of the added gain.

[amop]

Hi –

 

Thank you for your reply.

Here’s the detail…

My Strat goes into the Input 1 (instrument level) of an AudioFuse 16Rig.  The input is around -10dB to -6dB as recommended.  The signal is sent on Aux 1 to the H9000 via ADAT and input level on the H9000 measures about the same.  The FX Chain Mix is 100.  The IN and Out Gain for the algorithm (Atavachron in this case, but pretty much applies to all algorithms with this problem) is 0.  The Distortion Params settings:  Drive is 25 dB, Level -9 dB, Filter is 100%, Freq is 1034 Hz, Curve is 5, Flux is 0.78 ms, Distortion HiCut is 37515 Hz.

I get a terrible squeal much like amp feedback (I am using headphones so there is no speaker to pickup feedback that I can determine.)

If I turn down the Drive param the feedback goes away, but then the Drive loses the character I want.

The return of the wet signal is over ADAT to the Audiofuse 16Rig, and it comes in at about -18 dB (same as it leaves the H9000).

Let me know if you need more info.

Thank you of your help….

[tbskoglund]

You’re welcome.

I just tested this algorithm with a similar setup and it is working correctly for me using studio monitors. Not experiencing any squealing or feedback.

What happens when you use this same FX Chain setup using a thru algorithm and you turn up the input gain on either the FX Chain or algorithm input? I am pretty suspicious that there is a feedback loop happening somewhere in your setup unintentionally.

Some other things to try:

• Record some guitar in a DAW and then send that audio to/from the H9000 using the ADAT I/O. I can help you set that up if you are unfamiliar with this.
• Load an Oscillator algorithm followed by the distortion algorithm. This should just be a distorted sine wave with no FX Chain input, and that should help rule out if there is a feedback loop happening.

 

[amop]

Thank you very much for these suggestions.

It turned out to be something related to the I/O matrix I set up with my new audio interface.  I connected my previous one (Focusrite Clarett 8Pre) and it all worked fine.  I went back, tweaked the I/O settings and fixed the feedback issue (it was a duplication of Sends apparently – not 100% sure).

But then opened a can of worms with using the Emote plug-in in Logic (not the I/O plug-in as previously stated).  Seems I cannot turn on/off the plug-in from Logic once added to a track, only remove it, as the I/O has to be fixed in the AudioRig matrix.  Also strange behavior regarding mono and stereo.  But not a big deal. I usually don’t use the plug-in.  And I still need to get comfortable with the AudioRig.

Thank you again so much for your help – it sent me on the right trail.  The distortion algorithms are as wonderful as I remember them.

[tbskoglund]

Glad to hear you figured this out, new routing setups can be tricky.

Regarding Emote as a plug-in, making the plug-in active/bypassed will not accomplish much. Emote is simply a controller for the H9000; all of the audio routing must be done using the DAW, and the plug-in will still send the control information when it is bypassed. Whether or not you are processing in mono/stereo is determined by your FX Chain routing, and how you are sending audio to the H9000, the Emote plug-in being mono/stereo will not make a difference.

The key features that are available only when using Emote as a plug-in are listed here: https://cdn.eventideaudio.com/manuals/h9000/2.0/content/emote/plugin.html

[amop]

Sorry one last question:  I see that I can use the H9000 just fine with the Emote plug-in and not use the Logic I/O plug-in at all.  Am I missing some here?

[tbskoglund]

The Logic I/O plug-in is not required, that is just the typical way a user would send audio to/from an external device when using Logic.

It sounds like you have your audio routing figured out using your audio interface software, so you don’t need to use the I/O plug-in.

[amop]

Thank you again.

Yes, I figured that out today.  I had this all running a couple years ago but forgot the nuances, and then the new interface put me at square one.  Muscle memory coming back finally!  All good now.

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